Bulletin of the World Health Organization

Prioritizing risk factors to identify preventive interventions for economic assessment

Nick Wilson, Tony Blakely, Rachel H Foster, David Hadorn & Theo Vos

Volume 90, Number 2, February 2012, 88-96

Table 3. Risk factors retained for equity analysis and their role in health inequalities between Māori and non-Māori populations in New Zealand

Risk factor Relevant? (YLLs for Māori)a Inequalities between Māori and non-Māori populations in nine leading risk factors
Tobacco use Yes (8321) Smoking prevalence is much higher among the Māori than non-Māori people (i.e. 45% in Māori vs 21% for European and other ethnic groups),25 and this contributes to mortality inequalities.26–28 That is, Māori people have higher age-standardized mortality rates than non-Māori for ischaemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease and tobacco-related cancers (especially lung cancer, but also cancers of the stomach and uterine cervix).29–31
Alcohol, hazardous use Yes (Unknown) Hazardous alcohol use tends to be more common among the Māori than among the non-Māori population,32 although total alcohol consumption appears to be lower among Māori than among New Zealanders of European descent.33 Hazardous alcohol use increases the risk of motor vehicle crashes, which are major causes of mortality and morbidity among Māori, especially young Māori.34 Given their high smoking rates, Māori people are at particular risk for cancers involving synergies between smoking and alcohol use (i.e. for cancers of the oral cavity, pharynx, larynx and oesophagus),35 and individuals who drink heavily on a regular basis have significantly lower cessation rates.36
High blood pressure Yes (4445) High systolic blood pressure contributes more to avoidable cardiovascular disease mortality (both ischaemic heart disease and stroke) among both Māori men and women than in the non-Māori population.37 For example, the age-standardized mortality rate from ischaemic heart disease and stroke that is attributed to high systolic blood pressure is around 270 per 100 000 population for Māori males vs 140 for non-Māori males.37
High blood glucose Yes (Unknown) Diabetes is more prevalent among Māori people than among European New Zealanders (5.8% vs 4.3%, respectively).32 (In this table see also “physical inactivity” and “overweight and obesity”, the latter being a key component of higher mortality rates from diabetes in Māori people.)37
Overweight and obesity Yes (9901) The age-standardized mortality attributable to a high body mass index is relatively higher among the Māori than among the non-Māori population.37 Furthermore, the years-of-life-lost attributable to a higher than optimal body mass index are 21–24% in the Māori and 11% in the non-Māori population.37
Physical inactivity Yes (4624) The prevalence of sedentary behaviour is about 15–20% higher among Māori people than among Europeans and other ethnic groups.32 Nevertheless, regular physical activity levels are similar between Māori and non-Māori people (i.e. for at least 30 minutes of physical activity per day on 5 or more days of the previous week). Of note is the fact that this risk factor can modify other risk factors in this table (high blood glucose and overweight) that are relevant in terms of health inequalities between the Māori and non-Māori populations.
High blood cholesterol Yes (5232) Blood cholesterol levels contribute to more avoidable cardiovascular disease mortality (both ischaemic heart disease and stroke) among both Māori men and Māori women (compared with non-Māori people).37 E.g. for Māori males the age-standardized mortality rate from ischaemic heart disease and stroke that is attributed to high blood cholesterol is around 300 per 100 000 population, vs 180 for non-Māori males.37
Low fruit and vegetable intake Yes (2407) Māori women have significantly lower daily vegetable and fruit intake than European women or women of other ethnicity.32 Earlier survey data indicated lower intakes for Māori men and women.37 The possible role of green leafy vegetables in reducing the risk of diabetes38 may also be relevant.
Urban outdoor air pollution Possibly (Unknown) No definitive data on the contribution of such air pollution to ethnic inequalities appears to exist, although one recent study found a possibly stronger association of air pollution with mortality in the Māori than in the non-Māori population.39 Given this uncertainty, the air pollution risk factor was dropped from further consideration in our prioritization process.

YYLs, years of life lost.

a YLLs for Māori people discounted at 3% per annum based on 1996 data from a Ministry of Health report40 (for smoking and physical inactivity) and on 1997 data from Lawes et al.37 (for the other risk factors). We were limited to considering YLLs since none of the previous work in the New Zealand context considered disability-adjusted life years, which are the more appropriate measure.